Spring Loaded Pick

ABSTRACT

In one aspect of the invention, an apparatus for degrading natural and man-made formations includes a pick with an axially spring loaded pick comprising a central axis and being attached to a holder secured to a driving mechanism. The pick comprising a steel body with an axial shank disposed within a bore of the holder.

BACKGROUND OF THE INVENTION

Efficient degradation of materials is important to a variety ofindustries including the asphalt, mining, construction, drilling, andexcavation industries. In the asphalt industry, pavement may be degradedusing picks, and in the mining industry, picks may be used to breakminerals and rocks. Picks may also be used when excavating large amountsof hard materials. In asphalt recycling and trenching, a drum or chainsupporting an array of picks may rotate such that the picks engage apaved surface causing it to break up. Examples of degradation assembliesfrom the prior art are disclosed in U.S. Pat. No. 6,824,225 to Stiffler,US Pub. No. 20050173966 to Mouthaan, U.S. Pat. No. 6,692,083 to Latham,U.S. Pat. No. 6,786,557 to Montgomery, Jr., U.S. Pat. No. 3,830,321 toMcKenry et al., US. Pub. No. 20030230926, U.S. Pat. No. 4,932,723 toMills, US Pub. No. 20020175555 to Merceir, U.S. Pat. No. 6,854,810 toMontgomery, Jr., U.S. Pat. No. 6,851,758 to Beach, which are all hereinincorporated by reference for all they contain.

The picks typically have a tungsten carbide tip. Many efforts have beenmade to extend the life of these picks. Examples of such efforts aredisclosed in U.S. Pat. No. 4,944,559 to Sionnet et al., U.S. Pat. No.5,837,071 to Andersson et al., U.S. Pat. No. 5,417,475 to Graham et al.,U.S. Pat. No. 6.051,079 to Andersson et al., and U.S. Pat. No. 4,725,098to Beach, U.S. Pat. No. 6,733,087 to Hall et al., U.S. Pat. No.4,923,511 to Krizan et al., U.S. Pat. No. 5,174,374 to Hailey, and U.S.Pat. No. 6,868,848 to Boland et al., all of which are hereinincorporated by reference for all that they disclose.

BRIEF SUMMARY OF THE INVENTION

In one aspect of the invention, an apparatus for degrading natural andman-made formations includes an axially spring loaded pick comprising acentral axis and being attached to a holder secured to a drivingmechanism. The pick comprising a steel body with an axial shank disposedwithin a bore of the holder.

The tip of the pick comprises a material selected from the groupconsisting of cubic boron nitride, diamond, diamond like material,carbide, a cemented metal carbide, or combinations thereof. The materialmay be at least 0.100 inches thick, and may have a 6% to 20% metalbinder concentration by volume. The tip may also comprise a 0.050 to0.200 inch apex radius. The steel body of the tip may comprise a carbidecore and the tip may be brazed to the core.

A spring mechanism may be built into the holder which allows the tip toengage the formation and then recoil away from the formation lesseningdrag that would otherwise occur on the tip. The recoiling effect isbelieved to reduce wear caused from the drag. The recoiling effect isalso believed to degrade the formation in larger chucks than draggingthe tip against the formation surface. The spring mechanism may comprisea coil spring, a compression spring, a tension spring, Bellevillespring, wave spring, elastomeric material, gas spring, or combinationsthereof. The pick may also comprise an axial shank which is press fitinto the holder. The shank is secured within a holder which is securedto the driving mechanism.

The driving mechanism is a drum, chain, wheel, or combinations thereof.The driving mechanism may be attached to a trenching machine, excavatormachine, pavement milling machine, a coal mining machine, orcombinations thereof The driving mechanism may be attached to amotorized vehicle with a dampening element adapted to insulate thevehicle from the vibrations of the driving mechanism. The dampeningelement may comprise a shock, an elastic material, or a combinationthereof.

In another aspect of the invention, a method comprising the steps ofproviding an axially spring loaded pick comprising a central axis andbeing attached to a holder secured to a driving mechanism, the pickcomprising a steel body with an axial shank disposed within a bore ofthe holder and comprising a tip with a hardness greater than 4000 HV;positioning the driving mechanism adjacent to the formation; anddegrading the formation with a spring loaded pick by activating thedriving mechanism. The formation may be pavement, coal, soil, rock,limestone, or a combination thereof Also, the formation is an earthformation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective diagram of an embodiment of a plurality of pickson a rotating chain attached to a motor vehicle.

FIG. 2 is a cross-sectional diagram of an embodiment of a pick degradinga formation

FIG. 3 is a perspective diagram of an embodiment of a pick.

FIG. 4 is a cross-sectional diagram of the pick of FIG. 3.

FIG. 5 is a cross-sectional diagram of another embodiment of picks.

FIG. 5 a is a cross-sectional diagram of another embodiment of picks.

FIG. 5 b is a cross-sectional diagram of another embodiment of picks.

FIG. 6 is an orthogonal diagram of an embodiment of a dampening element.

FIG. 7 is an orthogonal diagram of an embodiment of a coal trencher.

FIG. 8 is an orthogonal diagram of an embodiment of a milling machine.

FIG. 9 is a perspective diagram of another embodiment of a trencher.

FIG. 10 is a flowchart illustrating an embodiment of a method fordegrading natural and manmade formations.

DETAILED DESCRIPTION OF THE INVENTION AND THE PREFERRED EMBODIMENT

FIG. 1 is a perspective diagram of an embodiment of a plurality of picks101 on a rotating chain 102 attached to a motor vehicle 103. Theplurality of picks 101 may be exteriorly mounted in a “V” pattern on thechain 102 to facilitate degradation and removal of a formation 104. Therotating chain 102 rotates in the direction of the arrow and cuts theformation forming a trench while bringing the formation cuttings out ofthe trench to a conveyor belt 105 which directs the cuttings to a sideof the trench The rotating chain 102 is supported by an arm 107. The arm107 may be raised while the machine is being transported or it may belowered for trenching as shown in FIG. 1. The position of the arm may becontrolled by a hydraulic piston and cylinder 108. The trenching machinemay move about the formation 104 by tracks 109, wheels, or a combinationthereof. A seat 106 for an operator is positioned on the side of themachine.

FIG. 2 is a perspective diagram of an embodiment of a pick 101 degradinga formation 104. The pick 101 comprises a carbide core 201 attached toan impact tip 202 and is press fit into a steel body 203. The steel body203 comprises a shank 204 which is press fit into a carrier 205 so as tohave a base 211 of the pick 101 flush against a distal end of thecarrier 205. The shank 204 comprises a flange 212 that keeps the shank204 interiorly locked to the carrier 205. The carrier comprises indents206 so as to stay within a holder 207. The holder 207 comprises fingers208 that interface with the indents 206 so as to limit the movement ofthe pick 101. The holder 207 comprises a spring mechanism 209 that maybe made of steel. The spring mechanism 209 may comprises a Bellevillespring or a stack of Bellevile springs to control the spring constant oramount of deflection. The springs are stacked in alternating directionsresulting in greater deflection. The spring mechanism 209 may also bestacked in the same direction creating a stiffer joint. Mixing andmatching directions allow a specific spring constant and deflectioncapacity to be designed. The pick 101 impacts the formation 104 in thedirection of the arrow 214 creating pressure on the spring mechanism209. With applied pressure the spring mechanism 209 compresses allowingthe pick 101 to retract slightly from the formation 104. When pressureis taken away from the pick 101 it returns to its original position.Spring loading the pick 101 is believed to cause the picks 101 tovibrate and move in a recoiling motion 214 across the formation 104which is optimized for the wear life of the pick 101. It is believedthat the recoiling motion 214 reduces the effects of drag and eventualwear on the pick 101. In some embodiments, when no pressure is appliedto the pick 101 at least one of the Belleville springs generally has a45° angle 213 from a pick central axis. When the pick 101 engages theformation 104 and pressure is applied the spring may potentiallycompress to a lesser angle. The holder 207 is welded to a plate 210horizontally bolted onto the chain 102 which moves in the direction ofthe arrow 215. As the pick 101 travels degrading the formation 104 itcarries the formation cuttings with it exposing new formation forengagement with adjacent picks.

FIG. 3 is a perspective diagram of an embodiment of a pick 101. The pick101 comprises a steel body 203 comprising a shank 204 extending from abase 303 of the steel body 203. The steel body 203 may comprise steelselected from the group consisting of 4140, 4130, S7, S5, A2, toolsteel, hardened steel, alloy steels, PM M-4, T-15, M-4, M-2, D-7, D-2,Vertex, PM A-11, A-10, A-6, O-6, O-1, H-13, EN30B, and combinationsthereof. A cemented metal carbide core 201 is press fit into the steelbody 203 opposite the shank 204. The steel body 203 may comprise alength 310 from a distal end to the steel base 303. In some embodimentsof the invention the carbide core 201 may be press fit into a majorityof the length 310 of the steel body 203. An impact tip 202 is bonded toa first end 306 of the core 201. The impact tip 202 comprises a workingsurface made of a superhard material 307.

The superhard material 307 may comprise diamond, polycrystalline diamondwith a binder concentration of 1 to 40 weight percent, cubic boronnitride, refractory metal bonded diamond, silicon bonded diamond,layered diamond, infiltrated diamond, thermally stable diamond, naturaldiamond, vapor deposited diamond, physically deposited diamond, diamondimpregnated matrix, diamond impregnated carbide, monolithic diamond,polished diamond, course diamond, fine diamond, nonmetal catalyzeddiamond, cemented metal carbide, chromium, titanium, aluminum, tungsten,or combinations thereof. The superhard material 307 may be apolycrystalline structure with an average grain size of 10 to 100microns.

Referring now to FIG. 4, the core 201 of the pick 101 comprises a secondend 401 and a diameter 402. The superhard material 307 may be at least4,000 HV and in some embodiments it may be 0.020 to 0.500 inches thick.In embodiments, where the superhard material is a ceramic, the materialmay comprise a region, near its surface, that is free of bindermaterial. Infiltrated diamond is typically made by sintering thesuperhard material 307 adjacent a cemented metal carbide substrate 405and allowing a metal (such as cobalt) to infiltrate into the superhardmaterial 307. As disclosed in FIG. 3 the impact tip 202 may comprise acarbide substrate 405 bonded to the superhard material 307. In someembodiments the impact tip 305 may be connected to the core 201 beforethe core is press fit into the body 203. Typically the substrate of theimpact tip 202 is brazed to the core 201 at a planar interface 406. Theimpact tip 202 and the core 201 may be brazed together with a brazecomprising a melting temperature from 700 to 1200 degrees Celsius.

The superhard material 307 may be bonded to the carbide substrate 405through a high temperature high pressure process. During hightemperature high pressure (HTHP) processing, some of the cobalt mayinfiltrate into the superhard material such that the substrate 405comprises a slightly lower cobalt concentration than before the HTHPprocess. The superhard material 307 may comprise a 6 to 20 percentcobalt concentration by volume after the cobalt or other binderinfiltrates the superhard material 307. The superhard material 307 mayalso comprise a 1 to 5 percent concentration of tantalum by weight.Other binders that may be used with the present invention include iron,cobalt, nickel, silicon, carbonates, hydroxide, hydride, hydrate,phosphorus-oxide, phosphoric acid, carbonate, lanthanide, actinide,phosphate hydrate, hydrogen phosphate, phosphorus carbonate, alkalimetals, ruthenium, rhodium, niobium, palladium, chromium, molybdenum,manganese, tantalum or combinations thereof. In some embodiments, thebinder is added directly to the superhard material's mixture before theHTHP processing and does not rely on the binder migrating from thesubstrate into the mixture during the HTHP processing.

The superhard material 307 may comprise a substantially pointed geometrywith a sharp apex comprising a radius of 0.050 to 0.200 inches. In someembodiments, the radius is 0.090 to 0.110 inches. It is believed thatthe apex may be adapted to distribute impact forces, which may help toprevent the superhard material 307 from chipping or breaking. Thesuperhard material 307 may comprise a thickness of 0.100 to 0.500 inchesfrom the apex to the interface with the substrate 405, preferably from0.125 to 275 inches. The superhard material 307 and the substrate 405may comprise a total thickness of 0.200 to 0.700 inches from the apex tothe core 204. The sharp apex may allow the high impact resistant pick101 to more easily cleave pavement, rock, or other formations.

A radius 407 on the second end 401 of the core 201 may comprise asmaller diameter than the largest diameter 402. A reentrant 408 may beformed on the shank 204 near and/or at an intersection 409 of the shank204 and the body 301. It is believed that placing the reentrant 408 nearthe intersection 409 may relieve strain on the intersection 409 causedby impact forces.

FIG. 5 is a cross-sectional diagram of other embodiments of picks 101.In one embodiment, the pick 101 is axially spring loaded with a coilspring 503. In another embodiment, the pick 101 is axially spring loadedwith an elastomeric material 504 disposed within the holder 207. FIG. 5a discloses spring mechanisms intermediate a base of the pick and theholder. In some embodiments, the spring mechanism may be a Bellvillespring 550 or it may be a stack of Bellville springs. In the embodimentsof FIG. 5 b, the spring mechanisms may be incorporated into the holders.The springs may be attached to a pivot 551 with a spring pushing on theholder 207. In some embodiments, the holder may comprise a geometry 552which inherently comprises a spring constant suited for trenchingapplications. Blocks may be used to control how the holders vibrate. Inother embodiments, the picks may comprise an arrangement similar to aspring loaded center punch or a piano hammer to affect the vibration inthe trenching action.

FIG. 6 is an orthogonal diagram of an embodiment of a trenching machinewith dampening elements which are in contact with an arm supportingblock on the machine. The block 602 comprises an axel 603 around whichan arm 107 pivots. In one embodiment the dampening element may be ahydraulic shock absorber 601 positioned between the block 602 and themotor vehicle 103 it may dampen the vibration felt by an operator 106 onthe machine. In some embodiments the block 602 also sits upon adampening element such as an elastomeric material 604. The operator 106is positioned near a control panel 601 that controls the operations ofthe motor vehicle 103. In other embodiments of the invention, thetrenching machine may be controlled remotely, so that an operatorpositioned on the machine may not be necessary. In such embodiments, themachine may be controlled through Wi-Fi, Bluetooth, radio wave, or acombination thereof.

FIG. 7 is an orthogonal diagram of an embodiment of a coal trencher 700.A plurality of picks 101 are connected to a rotating drum 701 that isdegrading coal 702. The rotating drum is connected to an arm 703 thatmoves the drum vertically in order to engage the coal. The arm 703 maymove by that of a hydraulic arm 704, it may also pivot about an axis ora combination thereof. The coal trencher 700 may move about by tracks109, wheels, or a combination thereof. The coal trencher 700 may alsomove about in a subterranean formation 704. The coal trencher 700 may bein a rectangular shape providing for easy mobility about the formation.

FIG. 8 is an orthogonal diagram of an embodiment of a plurality of picks101 attached to a rotating drum 801 connected to the underside of apavement milling machine 800. The milling machine 800 may be a coldplaner used to degrade man-made formations such as pavement 802 prior tothe placement of a new layer of pavement. Picks 101 may be attached tothe drum 801 bringing the picks 101 into engagement with the formation802. A holder 207 is welded to the rotating drum 801, and the pick 101is inserted into the holder 207. The holder 207 may hold the pick 101 atan angle offset from the direction of rotation, such that the pick 101engages the pavement at a preferential angle.

The pick 101 may be used in a trenching machine, as disclosed in FIGS. 1and 9. Picks 101 may be disposed on a rock wheel trenching machine 900as disclosed in FIG. 9. Other applications that involve intense wear ofmachinery may also be benefited by incorporation of the presentinvention. Milling machines, for example, may experience wear as theyare used to reduce the size of material such as rocks, grain, trash,natural resources, chalk, wood, tires, metal, cars, tables, couches,coal, minerals, chemicals, or other natural resources. Various millsthat may incorporate the composite material include mulchers, verticalshaft mills, hammermills, cone crushers, chisels, jaw crushers, orcombinations thereof. In some embodiments of the invention, rigid picksmay be used in combination with picks that are axially spring loaded.

Referring now to FIG. 10 a method 1000 of degrading natural or man-madeformations is disclosed. The method 1000 comprises a step 1001 ofproviding an axially spring loaded pick 101 attached to a holder 207secured to a driving mechanism degrading a natural or man-madeformations. The pick 101 comprises a steel body 301 with an axial shank302 disposed within a bore of the holder 202 and comprising a tip 305with a hardness of greater than 4000 HV. The method 1000 furthercomprises a step 1002 of positioning the driving mechanism adjacent tothe formation. The method 1000 further comprises a step 1003 ofdegrading the formation with a spring loaded pick by activating thedriving mechanism.

Whereas the present invention has been described in particular relationto the drawings attached hereto, it should be understood that other andfurther modifications apart from those shown or suggested herein, may bemade within the scope and spirit of the present invention.

1. An apparatus for degrading natural and man-made formations,comprising; an axially spring loaded pick comprising a central axis andbeing attached to a holder secured to a driving mechanism; and the pickcomprising a steel body with an axial shank disposed within a bore ofthe holder.
 2. The apparatus of claim 1, wherein the driving mechanismis a drum, chain, wheel, or combinations thereof.
 3. The apparatus ofclaim 1, wherein the tip comprises a material selected from the groupconsisting of cubic boron nitride, diamond, diamond like material, orcombinations thereof.
 4. The apparatus of claim 3, wherein the materialis at least 0.100 inches thick.
 5. The apparatus of claim 3, wherein thematerial of the tip comprises a 6% to 20% by volume concentration of ametal binder.
 6. The apparatus of claim 1, wherein the tip comprises a0.050 to 0.200 inch apex radius.
 7. The apparatus of claim 1, whereinthe steel body comprises a carbide core.
 8. The apparatus of claim 6,wherein the tip is brazed to the core.
 9. The apparatus of claim 1,wherein a spring mechanism is built into the holder.
 10. The apparatusof claim 1, wherein the spring mechanism comprises, a coil spring, acompression spring, a tension spring, Belleville spring, wave spring,elastomeric material, gas spring, or combinations thereof.
 11. Theapparatus of claim 1, wherein the driving mechanism is attached to amotorized vehicle.
 12. The apparatus of claim 10, wherein a dampeningelement is attached to the vehicle and is adapted to vibrationallyinsulate the vehicle from the driving mechanism.
 13. The apparatus ofclaim 12, wherein the dampening element comprises a shock.
 14. Theapparatus of claim 1, wherein the apparatus is a trenching machine. 15.The apparatus of claim 1, wherein a spring mechanism is disposed betweena pick body base and a pick holder.
 16. The apparatus of claim 1,wherein the spring mechanism disposed between the pick body and the pickholder comprises a Bellivelle spring.
 17. The apparatus of claim 1,wherein a spring mechanism is disposed between the driving mechanism anda holder.
 18. A method for degrading natural or man-made formations,comprising the steps of; Providing an axially spring loaded pickcomprising a central axis and being attached to a holder secured to adriving mechanism, and the pick comprising a steel body with an axialshank disposed within a bore of the holder and comprising a tip with ahardness greater than 4000 HV; Positioning the driving mechanismadjacent to the formation; Degrading the formation with a spring loadedpick by activating the driving mechanism;
 19. The method of claim 18,wherein the formation is pavement, coal, soil, rock, limestone, or acombination thereof.
 20. The method of claim 18, wherein the formationis an earth formation.